- In December 2018, media reported a potential cluster of cancers on the Bellarine Peninsula and historical use of an agricultural pesticide called dieldrin.
- Cancer is not one disease but a category of disease that can have very different causes and periods of time to develop.
- Cancer in young people is unusual and particularly distressing. It is often difficult to identify a cause or find explanation for the illness in children and young adults.
- To ensure any public health risk was thoroughly considered and that community concerns were addressed, the Acting Chief Health Officer conducted a review of cancer incidence data for the Bellarine Peninsula in 2019. View the report .
- This analysis considered a number of different cancer types together with the overall cancer rate in these areas and found no evidence of higher rates of cancer, including those thought to be associated with high levels of dieldrin exposure.
- Cancer Council Victoria conducted an epidemiological analysis using Victorian Cancer Registry data, which was completed in October 2019. View the report . This analysis was reviewed by the independent Expert Advisory Group. View the report .
- Following public hearings in May 2020 for the Parliament of Australia’s Senate Inquiry - Investigations into a possible cancer cluster on the Bellarine Peninsula, Victoria - the Department of Health requested Cancer Council Victoria extend their October 2019 epidemiological analysis of cancer rates in the Barwon Heads area to include data from the 1980s to the most recent. View the report .
- The Chief Health Officer sought a review by the independent Expert Advisory Group on Cancer Council Victoria’s extended epidemiological analysis. .
- Cancer Council Victoria’s extended epidemiological analysis and the Expert Advisory Group’s report were provided to the Senate Inquiry. The Senate Inquiry's final report can be found .
- Following a recommendation by the Senate Inquiry, the Department of Health engaged an independent science writer to produce a report for the Barwon Heads community.
- The report contains a summary of the results of the three previous studies (January 2019, October 2019 and March 2021).
- The report also contains general background information on cancer, autoimmune disease, disease clusters and their investigation. It also describes the chemicals used in the mosquito control program around Barwon Heads since records were kept from 1993. The science writer’s report can be found .
In December 2018, The Age reported a potential cluster of cancers on the Bellarine Peninsula purported to be related to historical use of the pesticide dieldrin in the area. Reports detailed a potential class action by those thought to be affected.
Dieldrin is classified as a probable carcinogen (Grade 2A) by the World Health Organisation's International Agency for Research on Cancer (IARC). This is based on 'limited evidence' for breast cancer in humans and 'sufficient evidence' for liver cancer in experimental animals. Specific community concerns were raised about a perception of a high number of cases of non-Hodgkin lymphoma, multiple myeloma, brain tumours and leukaemia in the area.
In response to this issue, the Chief Health Officer immediately initiated a review of cancer incidence rates for total cancers; breast and liver cancer; and non-Hodgkin lymphoma, multiple myeloma, brain cancers and leukaemia.
Whilst current research suggests no association between dieldrin and blood cancers, there was substantial speculation about the high number of cases of these cancers in particular and understandable distress and concern in the local community. This concern was particularly focused on these cancers in young people. The Chief Health Officer’s report aimed to provide a comprehensive review of cancer data relevant to the community's concerns.
The primary source of data for this report is the Australian Cancer Atlas, which includes comprehensive cancer incidence data for all of Australia by geographical area.
Analysis of these data indicates:
- no evidence of a higher rate of cancer overall in any geographical areas of the Bellarine Peninsula than elsewhere in Australia
- no higher number of the specific cancers of interest (breast, liver, non-Hodgkin lymphoma, multiple myeloma, brain cancers and leukaemia) than would be expected (based on the average cancer rates in Australia).
Assessment of the available epidemiological data has not found evidence of higher rates of the cancers assessed in any geographical areas within the Bellarine Peninsula. In addition, the hazard of concern (dieldrin) has not been identified as an agent that results in the cancers cited in the media.
Cancer in young people is unusual and particularly distressing. It is often difficult to identify a cause or to find explanation for the illness in children and young adults. Memories of these cases remain deep in communities and families for many years or a lifetime. Nothing in this report is intended to, nor should be taken to, dismiss the reports of individuals with cancers or of those friends and families who are all too aware of the tragedy that these cancers have had on many lives.
This report has examined cancer rates in defined areas known as Statistical Area Level 2 (SA2). This is the appropriate sized area to 'capture' sufficient cases of cancer to avoid the random fluctuation in rates that occurs when looking at smaller areas. As smaller areas and shorter time periods are examined, there is normal variation in cases and rates, due to chance alone. For example, if looking at areas of a few residential blocks, and one or two year time periods, it becomes apparent that there is large variation between areas and over time. Several areas will have no cases; some will have a few; and one or two areas may have several cases. This can sometimes be the basis for concern at an apparent increase in cases that occurs over particular years, or in very localised areas, or in particular age groups.
In 2020, the Parliament of Australia Senate Community Affairs References Committee commenced an Inquiry: Investigations into a possible cancer cluster on the Bellarine Peninsula, Victoria. Following public hearings in May 2020, the Department of Health requested Cancer Council Victoria extend their earlier analysis to include cancer rates in Barwon Heads from 1982 to 2019. The Chief Health Officer sought independent advice from the Expert Advisory Group. The Cancer Council Victoria’s extended analysis and Expert Advisory Group’s review are available below to download. The Senate Inquiry published its final report in June 2021.
In response to a recommendation from the Senate Inquiry’s final report, the Department of Health commissioned an independent science writer to write a report for the Barwon Heads community.
The Department of Health and the Chief Health Officer are committed to working with communities and relevant agencies to ensure that community concerns are conscientiously addressed, and that appropriate support and reassurance is provided.
The Chief Health Officer would like to express his heartfelt sympathy to all those affected by cancer on the Bellarine Peninsula and for the distress that concerns of a cancer cluster cause. He welcomes questions about, or critiques of, this report and recommends that anyone who wishes to further investigate the publicly available data does so.
The City of Greater Geelong’s website contains detailed information and FAQs about the investigation into the Bellarine cancer cluster concern.
For more information, formal reports of the investigation are available for download:
Reviewed 29 March 2023